1. Field
Embodiments described herein generally relate to methods and systems for producing phenol and acetone from cumene. More particularly, such embodiments relate to methods and systems for producing acetone having a reduced concentration of methanol.
2. Description of the Related Art
Phenol and acetone are produced in various processes, the most common of which is known variously as the Hock Process, the Hock and Lang Process, or the cumene-to-phenol process, among others. This process begins with the oxidation of cumene (isopropyl benzene) to form cumene hydro-peroxide (CHP). The CHP is then cleaved in the presence of an acid catalyst to form phenol and acetone. The phenol and acetone stream is subsequently neutralized in a salt solution and thereafter fractionated to recover the end-products phenol and acetone.
The cleavage and oxidation stages of the cumene-to-phenol process can increase the concentration of methanol in the production stream. In some processes that can use the acetone product it can be desirable to minimize the methanol content in the acetone product. For example, in the production of bis-phenol-A (BPA) from the acetone product, reduction of the methanol concentration can be beneficial because the methanol significantly reduces the life of the resin catalyst used to produce the BPA from phenol and acetone. However, the methanol can be relatively difficult to remove using traditional distillation systems, as the methanol can combine with acetone to form azeotropes with low boiling points. For example, in a typical acetone distillation column, the acetone product can have a residual methanol content of about 150 ppm to about 250 ppm. Such high residual methanol content in the acetone product can reduce the life of the BPA catalyst resin, resulting in increased costs of BPA production.
There is a need, therefore, for improved systems and methods for producing acetone having a reduced concentration of methanol.